 // 浏览器全屏方法 zhu18 2019-6-24
 //全屏
 function fullScreen() {
   var el = document.documentElement;
   var rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullscreen;
   if (typeof rfs != "undefined" && rfs) {
     rfs.call(el);
   };
   
   return ;
 }
 //退出全屏
 function exitScreen() {
   if (document.exitFullscreen) {
     document.exitFullscreen();
   } else if (document.mozCancelFullScreen) {
     document.mozCancelFullScreen();
   } else if (document.webkitCancelFullScreen) {
     document.webkitCancelFullScreen();
   } else if (document.msExitFullscreen) {
     document.msExitFullscreen();
   }
   if (typeof cfs != "undefined" && cfs) {
     cfs.call(el);
   }
 }

 //是否全屏
 function isFullScreen() {
   return document.isFullScreen || document.mozIsFullScreen || document.webkitIsFullScreen
 }

 //是否全屏
 function toggleFullScreen() {
  return isFullScreen()?exitScreen():fullScreen()
}

 export {
   fullScreen,
   exitScreen,
   isFullScreen,
   toggleFullScreen
 }